684 



CEMENTS, LIMES, AND PLASTERS. 



" These bricks were tested by burning them in an ordinary continu- 

 ous brick kiln, and a brick treated in this way withstood the fire suc- 

 cessfully and is still a good hard brick, the only change being in the 

 color, which is now a light buff. During the burning the loss in 

 weight averaged 6 ounces, which equals 4.47 per cent; and the absorp- 

 tion after burning was 16 ounces, or 11.9 per cent, after twenty-four 

 hours' immersion. 



" The following is the estimated cost of production, based on a pro- 

 duction of 10,000 bricks per day of ten hours: 



Labor. s. d. 



1 man at grinding-mill at 6d. per hour 5 



2 men at brickmaking machine, taking off, at 6d. 



per hour 10 



1 youth attending to moistening of material 3 6 



4 wheelers and stackers at 6d. per hour 1 



1 foreman. . 060 



246 



Cost in labor per 1000 bricks, say 4s. 6d. 



" To this must be added the cost of getting the slag to the machinery f 

 wear and tear, depreciation, and such charges as may be added for 

 power and steam. 



" As regards the slag, this should be run from the furnaces on to a 

 level floor and then broken up and taken to the machinery. This will 

 mean a little extra cost over that of running the slag in wagons and 

 depositing it in balls on the slag heap; but 6d. per ton should cover the 

 whole cost of casting the slag in this way and running it to the machinery. 

 Wear and tear on machinery will necessarily be high, considering the 

 wearing action of the slag. This will be well provided for at Is. 6d. 

 per 1000 bricks. 



" As to power and steam, this would be generated from the furnace 

 gases, and if not used for this purpose might be considered as wasted; 

 but assuming this at the value of coal, if such were used we should require 

 2 tons of coal per day, which, at 10s. per ton, works out at 2s. 6d. per 

 1000 bricks. If we allow 6d. per 1000 for generation, we get 3s. per 

 1000 bricks. 



" The cost of a complete plant such as described would be about 3000, 

 including buildings and all requirements. Taking depreciation at 7 

 per cent on the whole, and reckoning on 300 working days, we get 15s. 

 per day, or Is. 6d. per 1000 bricks. 



